<head>
    <link rel="stylesheet" href="../reset.css">
</head>

<style>
    .top_bar{
        margin: 0 auto;
        border: 5px solid red;
    }
    .clearfix::after{
        content: '';
        display: block;
        clear: right;
    }

    .child1{
        width: 200px;
        height: 200px;
        background-color: rgb(236, 194, 139);
        float: left;
    }
    .child2{
        width: 200px;
        height: 200px;
        background-color: rgb(130, 237, 116);
        float: right;
    }
    .header{
        height: 100px;
        background-color: rgb(99, 27, 231);
    }

</style>

<body>

    <div class="top_bar clearfix">
        <div class="child1">111111</div>
        <div class="child2">222222</div>
    </div>
    
    <div class="header">header</div>


</body>